Generally, in a power conversion apparatus, particularly, in an apparatus for performing a DC power conversion, a power supply apparatus that controls electric power for supplying to a load by an ON/OFF control of a switching element is well known.
The power supply apparatus may include an analog circuit system and a digital circuit system.
However, since the power supply apparatus of the conventional analog circuit system uses a switching power source realized by an analog circuit, it is difficult to change the setting of the power supply apparatus. Therefore, there is a problem when adjusting a ripple voltage or a switching frequency according to the specifications of the equipment to which power is supplied.
Further, since the power supply apparatus of the conventional digital circuit system uses a digital controller for a high frequency voltage regulator, which is implemented in a digital circuit, the power supply apparatus oscillates high frequency clock pulses. In particularly, when power consumption by the equipment to which power is supplied is small, since the power consumption of the digital controller is relatively large, there is a need to reduce the power consumption of the digital controller.